1: /*

     2:  * SPI interface whith the ST M95160 EEPROM

     3:  */

     4: 

     5: 

     6: #include        "pic1687x.h"

     7: static bit CHIP_SELECT  @ ((unsigned)&PORTB*8+5);       // CHIP SELECT

     8: int

     9: spi_read(long int addres)

    10: {

    11:         int data;

    12:         SSPBUF = 0x03;

    13:         CHIP_SELECT = 0;

    14:         do{}

    15:         while(!STAT_BF);

    16:         SSPBUF = 0x0;

    17:         do{}

    18:         while(!STAT_BF);

    19:         SSPBUF = addres;

    20:         do{}

    21:         while(!STAT_BF);

    22:         CKP = 0;

    23:         SSPBUF = 0;

    24:         do{}

    25:         while(!STAT_BF);

    26:         data = SSPBUF;

    27:         CKP = 1;

    28:         CHIP_SELECT = 1;

    29:         return(data);

    30: }

    31: 

    32: 

    33: void

    34: spi_write(unsigned char addres, unsigned char data)

    35: {

    36:         /* instruction */

    37:         SSPBUF = 0x02;

    38:         CHIP_SELECT = 0;

    39:         do{}

    40:         while(!STAT_BF);

    41: 

    42:         /* 16 bit addres */

    43:         SSPBUF = 0x00;

    44:         do{}

    45:         while(!STAT_BF);

    46: 

    47:         SSPBUF = addres;

    48:         do{}

    49:         while(!STAT_BF);

    50: 

    51:         /* 8 bit data */

    52:         SSPBUF = data;

    53:         do{}

    54:         while(!STAT_BF);

    55:         CHIP_SELECT = 1;

    56: }

    57: 

    58: 

    59: void

    60: spi_RDSR(unsigned unsigned char data)

    61: {

    62:         SSPBUF = 0x05;

    63:         CHIP_SELECT = 0;

    64:         do{}

    65:         while(!STAT_BF);

    66:         CKP = 0;

    67:         SSPBUF = 0;

    68:         do{}

    69:         while(!STAT_BF);

    70:         data = SSPBUF;

    71:         CKP = 1;

    72:         CHIP_SELECT = 1;

    73: 

    74: }

    75: 

    76: 

    77: void

    78: spi_WREN()

    79: {

    80:         SSPBUF = 0x06;

    81:         CHIP_SELECT = 0;

    82:         do{}

    83:         while(!STAT_BF);

    84:         CHIP_SELECT = 1;

    85: };

    86: 

    87: 

    88: void

    89: spi_WRDI()

    90: {

    91:         SSPBUF = 0x04;

    92:         CHIP_SELECT = 0;

    93:         do{}

    94:         while(!STAT_BF);

    95:         CHIP_SELECT = 1;

    96: };

    97: 

    98: 

    99: 

   100: void InitSPI(void)

   101: {

   102:         // SSPSTAT

   103:         STAT_SMP        = 0;    // INPUT DATA SAMPLED AT MIDDLE OF DATA

   104:         STAT_CKE        = 0;    // DATA TRANSMITTED ON RISING EDGE

   105:         STAT_BF         = 0;    // BF READY?

   106:         // SSPCON

   107:         SSPEN           = 1;

   108:         CKP             = 1;

   109: };